At the recent San Antonio Breast Cancer Symposium, a study conducted by HistoRx Inc and the University of Calgary was selected for discussion by the breast cancer specialists assembled for the conference. This study of 568 patients treated at the University of Calgary had several clinically relevant conclusions:

  • quantification of ER expression by AQUA analysis can provide a continuous recurrence risk assessment for patients being treated with tamoxifen
  • low level ER expressing patients show significant benefit from radiation treatment whereas radiation treatment showed no benefit in high-level, ER-expressing patients
  • response to radiation treatment can be predicted by quantification of ER expression

The study was designed to assess the objectivity and reproducibility of AQUA technology across institutions and across instrument platforms, and it found that "AQUA analysis, unlike any other system for measurement of in situ protein expression, can be standardized across platforms, operators and staining runs."

"There is a critical need for highly standardized and quantitative measurement of protein biomarkers in tissue specimens, particularly for estrogen receptor which is a key determinant of first-line therapy in breast cancer," stated Tony Magliocco, MD, associate professor in the departments of pathology and laboratory medicine and oncology at the University of Calgary, one of the authors of the study. "Laboratories throughout North America have discovered a significant lack of reproducibility in ER testing, and the AQUA platform may provide a solution to the problem."

The evaluation was conducted on a cohort of retrospectively collected breast cancer specimens from patients treated with tamoxifen with or without radiotherapy. The investigators hope to confirm the clinical findings in a second study with a prospectively assembled patient population, ideally from a cooperative group or other multi-institutional trial.

"HistoRx is pleased to see the data confirm our efforts in producing an objective, quantitative and reproducible measurement of ER in patient specimens," commented Jason Christiansen, PhD, senior director of operations for HistoRx and another author of the paper. "We were delighted to have the additional findings on disease recurrence and radiation response, and will follow up with the appropriate trials to confirm them."

Source: HistoRx Inc